Skill level

From DoomWiki.org

Each game skill level provides general difficulty settings that allow a greater variety of players to enjoy the game, allowing novices to face fewer opponents even with advantages for the player, and giving those who have mastered the game a challenge against many monsters, possibly with enhanced aggressiveness. Each skill level bears a colorful name suiting the character of the particular game being played and can be selected when the game starts or through additional options, particularly the -skill parameter.

This is the name or tag for each skill level according to the source code.

Each thing placed in a level (except for player starts) has cumulative bit flags (easy, normal, hard) marking on what skill levels it appears. The difference mainly amounts to larger and tougher comportments of monsters on the harder skill levels, but may also account for changes in the location of certain things. For example, in E3M6: Mt. Erebus the blue key is located in different places depending on the skill level.

Double means twice as much ammo is added to the player's current total when a corresponding item is picked up. For example, a rocket will provide 2 rockets, 4 shotgun shells will be counted as 8 shells, and a box of bullets will provide 100 bullets instead of the usual 50.

All cheat codes except idclev and iddt are disabled. Some source ports may change this or have internal workarounds.

See the Doom and Doom II table above for specific notes, as there are no differences in general, except that +50% means one and a half times as much ammo is added to the player's current total when a corresponding item is picked up.

The Marine takes 75% of the base damage. Slightly fewer monsters than usual are encountered.

1

Marine

The Marine takes 90% of the base damage.

2

Veteran

The Marine takes 170% of the base damage.

3

Nightmare

The Marine takes 350% of the base damage. All medikits are removed from the game, and the player's health steadily drains until it's 25 or below. To restore health, the player must use the Soul Cube (Artifact in RoE), or health stations. Player starts the game with respective artifact in their possession. Number of monsters is the same as on Veteran skill. This skill level must be unlocked by first completing the game on any other skill level.

The difficulty setting can be controlled by the console variable g_skill. The damage changes take effect immediately, but a map restart or change is necessary for the rest. For example, if a player begins the level on Recruit difficulty and then enters g_skill 3 in the console, immediately their health will begin its drop to 25 and they will receive Nightmare damage. However, the Soul Cube is not given, medkits remain in the level, and the amount of monsters does not increase.

Nightmare mode must be unlocked by completing the game first. This can be bypassed by changing the console variable g_nightmare.

The marine takes around 25% less damage from enemies. Gauntlet sections have fewer enemies.

1

Hurt Me Plenty

The standard difficulty. The marine takes normal damage and enemy numbers are unchanged.

2

Ultra-Violence

The Doom marine takes roughly 50% more damage and enemy numbers are increased.

3

Nightmare

The Doom marine takes about 90% more damage from enemy attacks to the point where a melee attack from an imp at the start is capable of one-hit killing him.

4

Ultra-Nightmare

Functions the same as Nightmare, but with the addition of Permadeath, meaning the player will need to complete the entire game without dying; saving is disabled apart from an automatic save in between stages, and if the player dies outside of a Rune Trial for any reason they must restart the game from the beginning. Depending on the version, this mode may be locked or unavailable altogether.

In addition to the five Doom standard skill levels, in vanilla Doom a skill level of 0 can also be specified, but only using the -skill parameter. Doing this empties maps of all things apart from the player starts. This does not work in many source ports. It also renders many levels that have boss trigger effects, require keys or use teleporters impossible to finish without the aid of cheat codes.

Early versions of Doom did not support "Nightmare!" skill. The initial mail-order releases were version 1.1 and only included the first four skill levels. The widely circulated version 1.2 added "Nightmare!" skill support. "Nightmare!" was added with the characteristic dark humor of the Doom games in response to any comments saying the game was too easy on "Ultra-Violence."[citation needed] After selecting "Nightmare!" from the main menu, the player is asked "Are you sure? This skill level isn't even remotely fair." The player must then confirm that he wants to play on Nightmare mode, a step which is unique to this skill level.

Some skilled players have created new challenges by defining custom rules, such as pacifist (not hurting monsters) and Tyson (fists, pistol, and chainsaw only).

In a similar vein to the custom rules, the 2016 reboot added the Ultra-Nighmare difficulty in a free update; while identical to the normal Nightmare difficulty for most purposes, it adds an "Ironman" feature in which the game is only saved after clearing a stage and dying for any reason (with the sole exception of dying during a Rune Trial) will force the player to start the game over from the beginning with a marker to indicate where the player died on the previous attempt.